Arctic Silver Help on Purchase please

Just realised that my Arctic Silver II tube is empty, I have looked around and find at overclockers website there is about 5 different types of this goo paste stuff what with cyramic type and that I am really confused.

I think I also read there is one where you have to mix a bit from Tube a with Tube b unlles I have been reading double.

So to replace my trusted Arctic Silver II tube which I think they are now on A.C No.5 or is it 6 can someone confirm I just need to look for the name "Arctic Silver 5" ?

Any link to decent prices welcome.

Also I have a local who sell Cooler master version, can this do the same job ?

AS 5 is the best, i use it to maintain incedible low temperature's, so much so i put a slower and quieter 80mm fan on top of a XP1700 that spins at 1900 rpm, rather than a 60mm that spin's at 5000rpm which is very noisey. This gives me a temp of about 49 degree's, but my other machine with proper fan is 36 degree's.

FWIW my Athlon XP2400+ running at 11.5x200 (2.3GHz on a 400MHz FSB with a Vcore of 1.8V) using Arctic Ceramique (£3.50 delivered) in combination with a thermaltake silent boost (ultra quiet HSF) at 100% load is currently 44C, case temp is 30C and room temp is 26C